Chances are you have heard the story of Phineas Gage at some point. Most of us get it in our General Psychology courses in high school and college, the story of a man who had a horrible accident and was never the same again — sort of like Harrison Ford in Regarding Henry, but the other way around.
The idea this anecdote supposedly supports is that personality = the brain, as evidenced by changes to the brain (like a spike through the head) that cause changes in personality. Pretty straightforward stuff. There’s only one problem.
It’s not true. Denyse O’Leary explains at Uncommon Descent:

The story is that in 1848, a tamping rod went through Gage’s head and totally changed his personality. He was “no longer Gage.” Which demonstrates that the mind and the self are an illusion created by the buzz of neurons in the brain. A textbook case.
I pointed out over dinner that there are good reasons to doubt this story. The prof was, of course, withering. Hundreds and hundreds of psych texts have told Gage’s story, he informed me, so how could it be false or questionable?
Well, I have written for newspapers most of my adult life, and one thing I know is this: Printing more copies of any type of information does not make it true. It makes it more widely disseminated.

Read the rest at Uncommon Descent.